Thrombin generation in nonclottable mixtures of blood and nonionic contrast agents.
The four newly introduced contrast agents--iopamidol, iohexol, ioversol, and ioxaglate--are of much lower osmolality than conventional agents, and claims have been made that they are substantially safer. A chromogenic assay for thrombin was applied to 1:1 (50%), 2:1 (67%), and 4:1 (80%) contrast agent-whole blood mixtures, each containing enough contrast agent to render them unclottable. Thrombin generation occurred in the nonionic-whole blood mixtures and increased with time. No thrombin could be detected in any ioxaglate-whole blood mixtures. The authors conclude that this difference presents a novel hazard in that iopamidol, iohexol, and ioversol permit thrombin generation to occur while inhibiting the fibrin polymerization step of blood coagulation, thus posing a significant, albeit theoretical, threat to patient well-being.
Kopko
P M
PM
Department of Pathology, Loma Linda University School of Medicine, Calif.
Smith
D C
DC
Bull
B S
BS
D000328:Adult; D001769:Blood; D001777:Blood Coagulation / Q000187:drug effects; D003287:Contrast Media / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007463:Iodobenzoates / Q000494:pharmacology*; D007472:Iohexol / Q000008:administration & dosage / Q000494:pharmacology*; D007479:Iopamidol / Q000008:administration & dosage / Q000494:pharmacology*; D007485:Ioxaglic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D013917:Thrombin / Q000032:analysis*; D013997:Time Factors; D014283:Triiodobenzoic Acids / Q000008:administration & dosage / Q000494:pharmacology*
D003287:Contrast Media; D007463:Iodobenzoates; D014283:Triiodobenzoic Acids; D007472:Iohexol; D013917:Thrombin; D007479:Iopamidol; C054871:ioversol; D007485:Ioxaglic Acid